In Did You Know? the National Geographic magazine team shares extra information we gathered to expand your knowledge of our featured subjects.

Say you want to illustrate a story with a pig just like those brought to Jamestown by the English colonists, but over the past 400 years domestic pigs in both Europe and the Americas have been carefully bred to be very different from those original pigs—where would you look for an "heirloom" pig?

You may have heard of heirloom tomatoes—varieties that are usually not found sitting next to the tough, flavorless, pale globes in your local supermarket. Often they're lumpy or odd colored or odd sized, and you find them at farmers markets or in home gardens. When you bite into one it tastes nothing at all like the commercially grown tomatoes that are shipped green to the store. Heirloom tomatoes burst with ripe tomato flavor, just like you might remember from your grandparents' farm, if you were lucky enough to have grandparents with a farm.

Well, tucked away on an island off the coast of Georgia lives a population of some 2,000 wild swine that are about the closest we can find today to the pigs brought to North America by early European explorers and settlers. In the 1500s, when Spain was scouting the southeast of what would become the United States, Spanish explorers left a population of pigs on an island as a free-roaming larder for future trips to the area. The island's name is Ossabaw, one of the Sea Islands, and it lies about 20 miles (30 kilometers) south of Savannah.

The pigs went feral quickly and over the centuries adapted to their environment. They got a bit smaller, to fit their small space, in a process called island dwarfism, and they packed pounds on their smaller frame by laying up fat for the feast-or-famine cycles of abundance on the island. But in general they stayed true to their European roots and are now often used at living history sites such as Colonial Williamsburg to represent colonial-era hogs.

Despite being quite cute, with round bellies, stubby legs, and longer snouts than the average pig, Ossabaws were originally brought to American shores as a food source, and there is still demand for them as a gourmet meat. Their thick layer of fat renders them particularly tasty, especially when roasted whole. The Slow Food Association, dedicated to preserving noncommercial heritage foods, has put Ossabaws on its short list of endangered foods called the Ark of Taste.

Their isolation has also caused the Ossabaw Island hogs to develop a couple of medical conditions of interest to scientists—their bodies can tolerate high concentrations of salt water in their diet (salt pork, anyone?), and they have developed non-insulin-dependent diabetes. As human bodies and the pigs' bodies are similar in many respects (blood vessel construction, weight, organ size, and more), testing can be done that may help doctors treat the growing number of human diabetics in the United States.

The feral pigs' future on Ossabaw Island itself is ultimately uncertain. The most recent management plan for the reserve calls for the population numbers to be kept stable by hunting and trapping, and there is some pressure for them to be eradicated altogether from the island's habitat. Since they are an introduced species and reproduce quickly, they wreak havoc on local populations of plants and animals including the endangered loggerhead turtles that nest on the island. At the moment, due to quarantine restrictions, it is difficult to take Ossabaw pigs off the island. Perhaps careful handling of mainland populations can allow the historic Ossabaw Island hog to flourish in a controlled environment without endangering other species.